Motor vehicle manufacturers and suppliers of safety restraint systems constantly strive to provide enhanced occupant protection systems for restraining an occupant in the event of impact or rollover events. One class of restraint systems are referred to as active restraints in which the vehicle occupant deploys the system through some action such as fastening a seatbelt latch plate into a buckle. Most frequently, so-called three-point belt systems are used in passenger motor vehicles, particularly for front seat occupants. In a three-point restraint system, a separate lap belt or a lap belt segment of the belt webbing crosses the occupant's pelvis and is primarily employed for restraining displacement of the pelvis during an impact or rollover event. A shoulder belt or a shoulder belt segment of the webbing normally passes diagonally across the upper torso of the occupant, from a lower hip point, across the occupant's chest and to an anchorage. These systems function well to provide vehicle occupant restraint and protection, is but there remains a constant striving for enhanced performance.
Vehicle manufacturers and their suppliers along with governmental regulatory bodies impose safety related regulations affecting the design of automobiles and equipment provided on them for occupant protection. In addition to the active restraints mentioned previously, so-called passive systems such as inflatable restraints are also commonly implemented. Governmental agencies as well as the vehicle manufacturers and their related supply chain participants utilize surrogate devices referred to as an anthropomorphic test device (or dummy) (ATD) for testing the performance of vehicle impact safety systems. Vehicles sold or used in the United States must meet certain National Highway Traffic Safety Administration (NHTSA) rules, referred to as Federal Motor Vehicle Safety Standards (FMVSS) for impact protection and safety. Corresponding sets of regulatory requirements are in place throughout the world. For establishing compliance with some of these standards, an ATD known as the Hybrid III (or HIII) is currently used for evaluation. The Hybrid III test dummy provides a great deal of instrumentation data which has been correlated to human impact tolerance which in turn gives rise to certain minimum performance values established by the applicable standards.
More recently, a next-generation ATD is being deployed referred to as the THOR (or Test device for Human Occupant Restraint) dummy. The THOR dummy was developed to provide even more detailed and sophisticated data related to human impact tolerance and is believed to have a higher degree of biofidelity than the current Hybrid III dummy. Adoption of the THOR dummy is likely to be an impetus for further safety regulation promulgation and also provides a tool for manufacturers to enhance occupant protection. Studies with the THOR dummy along with field data have shown that high chest deflection during a frontal impact event is correlated to occupant injury severity and fatality. This information in part is spurring development of advanced vehicle restraint systems which effectively reduce chest deflection.
Presently available motor vehicles typically combine active and passive restraint systems. In frontal impact conditions, both belt-type active restraint systems and frontal impact inflatable restraints combine to restrain the occupant. However, even with the use of such systems cooperating to provide occupant restraint, there remains a desire for further enhancements in frontal impact protection and a reduction of chest deflection in particular. Reductions of chest deflection may be provided in accordance with this invention through improved restraint of the occupant's pelvis during a restraint event.